Hydraulic oscillator for the shaft of an agitator



Aug. 26, 1952 c. w. OSMOND 2,608,183

HYDRAULIC OSCILLATOR FOR THE SHAFT OF AN AGITATOR Filed Jan. 6, 1949 ZJLJSQ I] 16 V Z6. 25- 4 4 I P 1M 'ENTOR. REVG. Gin/rues M aswolva,

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AT'IO PNEYS- Patented Aug. 26, 1952 UNITED STATES HYDRAULIC OSCILLATOR FOR THE SHAFT OF AN AGITATOR Charles W. Osmond, Cincinnati, Ohio, assignor to Littleford Bros. 1110., Cincinnati, Ohio, a corporation of Ohio Application January 6, 1949, Serial No. 69,560

7 Claims.

My invention relates to an agitator oscillating means primarily for use with heating kettles designed for melting bituminous materials, such as asphalt or the like, wherein the resistance offered to the agitator is very great, particularly at the commencement of the heating.

My oscillating means is particularly adapted for use with an agitator similar to that shown in my copending patent application, Serial No. 59,891, filed November 13, 1948, and now abandoned, and entitled Agitator.

In the heating-of material for coating large pipe lines, a large heating kettle is used. The frozen material is placed in the kettle in large pieces, sometimes weighing as much as 200 pounds. The primary melting of this material into a liquid is slow and difiicult and presents a decided strain on the agitator and the oscillating means therefor, since these large pieces must be moved about by the agitator.

After the material has become melted, it is extremely stiff and hard to manipulate since the binder is relatively thick and the resulting mix is quite viscous. In the usual type of drive or oscillating means for agitators, since the mechanism is placed under agreat strain it is very apt to stall or break. It is also important that the control of the agitator paddle be manually available at the commencement of the heating so that the agitator may be stopped at any instant, reversed,

advanced, or speeded up.

It is an object of my invention to provide an oscillating means for an agitator shaft which is motivated by hydraulic pressure, thus securing a rugged and powerful actuating force.

It is a further object of my invention to provide an oscillating mechanism which will oscillate automatically, but which may be interrupted at any instance and the agitator paddle slowed down, speeded up, or reversed manually without interfering with the automatic features.

It is an object of my invention to provide an oscillating mechanism for agitators which instantly stops when overloaded without injuring any of the parts of the mechanism, or injuring the agitator itself.

It is a further object of my invention to provide a means for oscillating an agitator wherein the length of the oscillating strokes may be adjusted to any fraction of the full strokes without the necessity of complicated adjustments.

These and other objects of my invention which will be set forth hereinafter or which will be apparent to one skilled in the art upon reading these specifications, I accomplish by that certain construction and arrangement of parts of which I shall now describe an exemplary embodiment.

Reference is now made to the drawings which form a part thereof and in which:

Figure 1 is a'front elevation of a melting kettle showing my novel means for oscillating the agitator therein. The kettle bottom and the agitator itself is shown in broken lines.

Figure 2 is a diagrammatic view of the valve control of the double acting hydraulic ram which actuates my mechanism.

Briefly, in the practice of my invention, I provide a reversible double acting hydraulic ram with its piston connected to a crank arm mounted on the shaft carrying the agitator. There is a valve which controls the direction of throw and reversal of a hydraulic ram mounted on a portion of the housing of the melting kettle and which is actuated by contacts associated and moving with the agitator shaft. These contacts are adjustable so that the length of stroke of the agitator before its reversal may be varied. This reversing valve also has manual means for changing its position so that at any time during the automatic reciprocation of the agitator, the ram may be reversed or moved slightly in either direction by the manual means on the valve. There is also a three way valve in the hydraulic line running to the ram which may be manually operated to stop or start the ram and the driven agitator at anytime. I provide a relief valve either in the hydraulic pump or in the hydraulic line from the pump which is adjustable so that the pressure in the ram may be limited or changed at will, and by varying the speed of the hydraulic pump itself which drives the hydraulic medium to the ram, the speed of the ram and the agitator may be changed.

Referring to the drawings, I provide a crank arm I which is fastened to the agitator shaft 2 by welded plates 3. To the end of the arm I is coupled the piston rod 4 of the reversible double acting hydraulic ram'5. The cylinder of the ram 5 is coupled to a'bracket or portion of the frame 6 of my device so that the reciprocation of the piston in the ram 5 oscillates'the shaft 2;

Welded to the plate 3 and projecting therefrom, I provide an arm land on the end thereof and normal thereto, I preferably provide a slide 8. v

The pilot valve 9 and the operating valve 38 for controlling reversal of the ram 5 is shown in cross section in Figure 2. Both of these valves are of a well-known type and the pilot valve 9 consists of a core l0 having passageways H and I2 connectable by moving the core lll to inlet l3 and either pilot outlet M or I 5. At the same time,

it connects either port I4 or Hi to an outlet or exhaust passage l6 which communicates with the sump ll of the hydraulic medium. The core of this pilot valve 9 is actuated by projecting fingers I9 and 20 and a manual operating handle 2| projecting in the opposite direction. There is a dead center arrangement in conjunction with the core It! so that the core l may not be stopped between the two positions described above.

The operating valve 30 contains a reciprocating plunger 3| having apertures 32 and 33 divided by a partition 34. The line I from the pilot valve 9 is connected to one end of the cylinder 35 of the operating valve 30, while the line [4 from the pilot valve 9 is connected to the other end of the cylinder 35 of the operating valve 30. An intake line 36 is connected to a port 3'6 substantially centrally located in the cylinder 35 of the operating valve. This line 36 is coimected to the outlet of the pump 24 on the other side of the relief valve 26 and a three way valve 31. There are lines 38 and 39 running from the cylinder 30 of the operating valve to each end of the hydraulic ram 5 so they will discharge on opposite sides of the piston in the hydraulic ram. There are exhaust passageways 40 and 4| connected with the cylinder 30 of the operating valve and discharging into the sump IT.

The operation of the pilot valve 9 and operating valve 30 is as follows. 24 forces hydraulic fluid through the operating line 36 to the cylinder of the operating valve 39. There is a bypass which enters the pilot valve 9 through the port 13 and depending upon the position of the core Id of the pilot valve 9, this fluid under pressure is forced through either passageway E5 or 14 to one end or the other of the operating valve 30. In Figure 2 of the drawing, the arrangement of the cores of the two valves is such that fluid under pressure has forced the core 3| of the operating valve 30 upwardly and permitted fluid to flow through the line 36 into the chamber 33 in the piston 31 in the operating valve 30 and out through line 39, thus forcing the piston of the ram 5 upwardly. The discharge above the piston of the ram 5 flows through the line 38 through the chamber 32 of the operating valve 30 and out through the exhaust line 40 into the sump I1. When either the fingers l9 or 20, or the handle 2| of the pilot valve 9 is actuated to throw the core I0 of the pilot valve 9 to its other position, the flow through the operating valve 30 is reversed, i. e. fluid will flow from the pilot valve 9 through line 15 forcing the piston 31 of the operating valve downwardly. This will permit the flow from the line 36 to go through line 38 above the piston in the ram 5 forcing the ram piston downwardly. The fiuid under the piston of the ram 5' will exhaust through passageway 39, chamber 33 in the operating valve 30 and exhaust line 4|. As is apparent from the drawing, the fluid on the low pressure side of the piston 31 in the operating valve 30 will exhaust alternately through lines l3 or l5 and through lines l5 attachedto the pilot valve 9 to the sump [1.

There is a three way valve 31 either associated with the pump 24 or in the line 25 leading from the pump 24. The manually operated relief valve 26 may be incorporated in the pump 24 or located in the same line 25. If the relief valve 23 is in the line 25 it may be preferable to provide a discharge line from the relief valve 26 to the sump I! depending upon the type of pump 24 used.

The pilot valve 9 is mounted on a portion of the housing of the apparatus so that the core The operating pump operating fingers I9 and 20-may be contacted by contacts 22 or 23 slidably mounted on the slide 8, as is apparent in Figure 1. This positioning is such that the rocking of the shaft 2 will bring either contact 22 or contact 23 against either finger H) or 20 and shift the core I0 of the pilot valve 9 so that the ram 5 will be reversed.

Of course, this reversal may be manually accomplished by means of the lever 2 I.

The operation of the device is as follows:

When the kettle is newly charged with large pieces of frozen material, the agitator 28 is usually first actuated by manually operating the handle 2! which controls the valve core I0 of the pilot valve 9 moving the agitator 28 a relatively short distance in one direction and then in the other. The agitator may be stopped by actuating the valve 31 at any time in its travel. By manipulating the handle 2| together with the valve 31, the agitator may be caused to move backwardly and forwardly any desired distance and inched back and forth until the material within the kettle is sufficiently softened up to permit the automatic operation of the hydraulic ram 5 to take over. In the automatic operation of the device, the conacts 22 and 23 are arranged on the slide 8 at predetermined positions to permit the double-acting hydraulic ram 5 to rock the agitator 28 back and forth, the reversal being accomplished by the impingement of the contacts 22 and 23 on either finger l9 or 20. If it is desirable to increase the stroke in either direction, it is only necessary to move the contacts 22 or 23 up or down the slide 8. If an obstruction should be met or the viscosity of the mix becomes such as to stall the agitator 28, nothing is injured. The pressure in the lines merely overcomes the resistance of the relief valve 26 and the fluid is bled back into the sump and further flow is prevented. When the agitator 28 stalls, the movement of the agitator may be reversed by manipulating the lever 21 and the agitator may be operated by hand until the resistance is overcome when the whole device will go back on automatic operation.

If it is desirable to limit the power placed on the agitator, it is merely necessary to adjust the relief valve 26, while if it is desirable to change the speed of the agitator, it is merely necessary to change the speed of the pump 24 or permit bleeding or bypassing of the fluid under pressure.

Since the actuation of the device is hydraulic, there is nothing to break upon the stalling of the drive, as is the case with a mechanical or electrical drive.

The control of the agitator is very flexible and there is nothing to become jammed or get out of order. The device is simple and rugged and any necessary repairs or replacements are quickly and easily made in the field.

While I have shown the arm I projecting on the opposite side of the shaft 2 from the arm I, it is to be understood that the arm 1 may be placed at any'angle convenient or the slide 8 may be mounted on the end of the arm I, if desirable, or in any other position since it is merely necessary that the contacts 22 and 23 straddle and contact the fingers l9 and 20 of the pilot valve 9 upon the oscillation of the shaft 2.

While in the description and in the drawings I have referred to and shown a double-acting hydraulic ram 5, it is to be understood that it is within the contemplation of my invention to provide two or more single-acting hydraulic rams opposed to each other with their controls appropriately arranged.

It is to be understood that modifications may be made in my invention without departing from the spirit thereof, and I do not intend to limit myself otherwise than as pointed out in the claims which follow.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. Means for oscillating the shaft of an agitator which comprises at least one hydraulic ram having a reciprocating piston operatively connected to a crank arm mounted on the shaft, a hydraulic reversing system for said ram including a pilot valve control having projecting operating fingers, means mounted on and oscillating with the shaft of the agitator and having contacts engageable with said fingers at a predetermined position of rotation of said shaft so as to limit the oscillation of the agitator and a manual control associated with said pilot valve for manually operating the same.

2. Means for oscillating the shaft of an agitator which comprises at least one hydraulic ram having a reciprocating piston operatively connected to a crank arm mounted on the shaft, a hydraulic reversing system for said ram including a pilot valve control having projecting operating fingers, an arm radially mounted on said shaft and terminating in a slide normal to said arm, at least one contact adapted to move an operating'finger slidably mounted on said slide, said operating fingers being mounted in the path of said contact so that the rotation of the shaft will move said fingers at a predetermined position.

3. Means as set forth in claim 2 wherein two contacts are slidably mounted on the slide with the pilot valve control operating fingers positioned between them.

4. Means for oscillating the shaft of an agitator which comprises at least one hydraulic ram having a reciprocating piston operatively connected to a crank arm mounted on the shaft, a hydraulic reversing system for said ram including a pilot valve control having projecting operating abutment means, means mounted on and oscillating with the shaft of the agitator and having contacts engageable with said abutment means at a predetermined position of rotation of said shaft so as to limit the oscillation of the agitator,

6 said pilot valve being capable of independent manual operation.

5. Means for oscillating the shaft of an agitator which comprises at least one hydraulic ram having a reciprocating piston operatively connected to a crank arm mounted on the shaft, a hydraulic reversing system for said ram including a pilot valve control having projecting operating abutment means, an arm radially mounted on said shaft and terminating in a bar normal to said arm, at least one contact adapted to move said abutment means mounted on said bar, said operating abutment means being mounted in the path of said contact so that the rotation of the shaft will move said abutment means at a predetermined position.

6. Means as set forth in claim 5 wherein two contacts are mounted on the bar with the pilot valve control operating abutment means positioned between them.

7. Means for oscillating the shaft of an agitator which comprises at least one hydraulic ram having a reciprocating piston operatively connected to a crank arm mounted on the shaft, a hydraulic reversing system for said ram including a pilot valve control having projecting operating abutment means, an arm radially mounted on said shaft and terminating in a slide normal to said arm, at least one contact adapted to move said abutment means slidably mounted on said slide, said operating abutment means being mounted in the path of said contact so that the rotation of the shaft will move said abutment means at a predetermined position.

CHARLES W. OSMOND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Geiger Dec. 9, 

